Mobile phase: Dissolve 3.0 g of sodium 1-heptanesulfonate in 740 mL of water in a suitable 1000-mL vessel, and add 3.8 mL of triethylamine. Adjust the resulting solution with phosphoric acid to a pH of 3.5, and dilute with water to 750 mL. Add 250 mL of acetonitrile, and adjust with phosphoric acid to an apparent pH of 3.7.

Standard solution: 1.0 mg/mL of USP Neotame RS in Mobile phase

Sample solution: 1.0 mg/mL of Neotame in Mobile phase.

[NoteThis solution is stable for up to 32 h when stored at a temperature of 010. ]

[NoteUse acid-cleaned (mixture of 5% nitric acid and 5% hydrochloric acid followed by rinsing with water) autosampler cups and volumetric glassware to avoid contamination. For the preparation of all aqueous solutions and for the rinsing of glassware before use, use water that has been passed through a strong-acid, strong-base, mixed-bed ion-exchange resin. Select all reagents to have as low a content of lead as practicable. Store standards and samples in acid-cleaned polyethylene containers. ]

Diluent: Transfer 2 mL of lead-free nitric acid into a 1000-mL volumetric flask, dilute with water to volume, and mix.

Standard stock solution: 79.9 mg of lead nitrate in 100 mL of Diluent in a 500-mL volumetric flask, and dilute with Diluent to volume. Transfer 10.0 mL of the resulting solution into a 100-mL volumetric flask, and dilute with Diluent to volume. Each mL of the Standard stock solution contains the equivalent of 10 µg of lead.

Standard solution A: Dilute an aliquot of the Standard stock solution with Diluent to obtain a solution having a concentration of 0.03 µg/mL.

Standard solution B: Dilute an aliquot of the Standard stock solution with Diluent to obtain a solution having a concentration of 0.015 µg/mL.

Sample solution: Transfer 160 mg of Neotame to a 10-mL volumetric flask. Dissolve in and dilute with Diluent to volume.

Correct the area responses of the Sample solution, Standard solution A, and Standard solution B for the Blank area response. Generate the appropriate lead calibration algorithm, and determine the lead concentration in the Sample solution, in µg/mL.

Calculate the ppm of lead in the portion of Neotame taken:

Result = (C/W) × V × F

C

=

= blank-corrected lead concentration in the Sample solution (µg/mL)

W

=

= weight of Neotame taken to prepare the Sample solution (mg)

V

=

= volume of the Sample solution, 10 mL

F

=

= conversion of mg to g

Acceptance criteria: NMT 2 ppm

• Related Compounds

Mobile phase and Chromatographic system: Proceed as directed in the Assay.